Given a reasonable likelihood that long-term reduction of dietary fat to 20% of calories might reduce risk for breast cancer, our specific aim is to assess and compare the effectiveness of three approaches to reducing dietary fat intake in women at high risk for carcinoma of the breast. The diets are designed to isocalorically reduce fat intake from the current level of approximately 40% of calories to 20% of calories for an extended time period. We will randomly assign 60 women, ages 40-44 years to one of three intervention methods: 1) a goal oriented, behavior modification method; 2)\a traditional, dietary prescription method implemented in one stage; and 3) a traditional, dietary prescription method implemented in three gradual steps. Subjects will be drawn from the Cincinnati Breast Cancer Detection Center follow-up population and selected because of one or more positive risk factors for breast cancer: [1) concern incidence in either mother or sibling; 2) first delivery after age 30; and/or 3) positive history of benign breast tumors.] Thus, all subjects will be equally motivated to adopt dietary changes which, on the basis of recent research, might reduce risk to breast cancer. All subjects will receive seven dietary evaluation/intervention visits: an initial evaluation visit; four intervention visits three weeks apart; and two final evaluation visits, one month and one six months after the intervention process. Although current research indicates that long-term reduction in fat consumption could result in reduced risk to breast cancer, and although the National Cancer Institute has funded proposals in the areas of dietary fat reduction and cancer incidence including our proposal, there are no controlled studies of the effectiveness of different dietary intervention methods in reducing total fat intake. This study will provide preliminary data on the effectiveness of dietary intervention methods in a controlled study. By using and by comparing three alternative methods available to dietitians for the reduction of fat intake, our overall goal is to determine the most effective, best tolerated approach to reduce dietary fat to 20% of calories, while retaining nutritionally sound, adequate diets, and minimizing recidivism. By providing a better understanding of the best approach towards reducing dietary fat, this study should markedly facilitate other current and projected long-range studies directed at reduction of risk for breast and/or colon cancer through reduction in dietary fat.